Method and apparatus for manufacturing high concentration ozone gas

ABSTRACT

A method and apparatus for manufacturing high concentration ozone gas, characterized by employing a pressure swing adsorbing apparatus having a plurality of adsorbing layers filled with ozone adsorbent, in which the ozone adsorbent is one or two or more kinds of adsorbent selected from the group consisting of high silica pentasyl zeolite, dealuminized fogersite, and mesoporous silicate. A method and apparatus for manufacturing high concentration ozone gas, characterized by employing a TSA adsorbing system, discharging oxygen concentrated gas at a relatively low temperature from the adsorbing layers, passing purge gas at a relatively high temperature into the adsorbing layers in the desorbing process in an opposite direction of the gas flow in the adsorbing process, and recovering the concentrated ozone gas continuously, in which the ozone adsorbent is one or two or more kinds of above adsorbent, and the gas containing ozone from the ozone generating apparatus is cooled by the oxygen concentrated gas at a relatively low temperature flowing out from the adsorbing layers in the adsorbing process.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a manufacturing method of highconcentration ozone gas and an apparatus thereof using a pressure swingadsorption apparatus (PSA apparatus) having plural adsorbing layersfilled with a specific high silica ozone adsorbent large in thedifference of ozone adsorbing amount between adsorption pressure anddesorption pressure, that is, the ozone adsorbing capability.

[0002] The invention also relates to a manufacturing method of highconcentration ozone gas and an apparatus thereof for concentrating ozoneby a temperature swing adsorption system for changing over an ozoneadsorbing process at a relatively low temperature and an ozone recoveryprocess at a relatively high temperature, by using a specific ozoneadsorbent having a high ozone adsorbing capability even in the presenceof water.

[0003] Ozone is produced by using silent discharge apparatus or waterelectrolytic apparatus, but the ozone gas obtained from theseapparatuses are low in concentration, and it is usually used afterconcentrating by an ozone adsorbing apparatus or the like.

[0004] As an ozone concentrating apparatus, an oxygen recycling ozonegenerating apparatus using liquid oxygen is proposed (Japanese PatentApplication Laid-open No. 53-64690). A schematic diagram of thisapparatus is shown in FIG. 15. It is a feature of this apparatus thatliquid oxygen is used as the oxygen material. This liquid oxygen 31 isfed into an ozone generating apparatus 32, and the gas containing theozone is cooled to about −60° C. by a heat exchanger 33 and arefrigerating machine 34, it is further fed into an ozone adsorbingtower 35 filled with silica gel to adsorb ozone, the gas containingoxygen flowing out from the adsorbing tower 35 is fed into the heatexchanger 33 to cool the gas containing the ozone, and it is returned tothe material side of the ozone generating apparatus 32. On the otherhand, the adsorbing tower 35 having adsorbed the ozone is transferred tothe desorbing process, and the air 37 dried by a dryer 36 is heated by aheat exchanger 38, and is fed into the ozone adsorbing tower 35 to beheated, purged and desorbed, and a concentrated ozone gas 37 isrecovered, while the desorbed concentrated ozone gas 39 is fed into theheat exchanger 38, and the dried air is heated. Consequently, theregenerated adsorbing tower 35 by desorbing the ozone is transferredfrom the desorbing process to the adsorbing process.

[0005] Thus, the silica gel is known as ozone adsorbent, but since it isextremely large in the moisture adsorbing capability as compared withozone, if moisture is present in the gas contacting with the adsorbent(the gas to be treated, purge gas, and the like), the moisture ispreferentially adsorbed by the silica gel, and it is hard to desorb theonce adsorbed moisture, and the moisture is accumulated, and hence it isdifficult to maintain a specific ozone adsorbing capability. As aresult, an extremely large amount of silica gel is needed formaintaining a specific gas treating capacity, and the adsorbingapparatus itself is increased in its size. Besides, when adsorption anddesorption of moisture are repeated, the silica gel is powdered and maybe lowered in the adsorbing capability.

[0006] In the aforesaid apparatus, using liquid oxygen as oxygenmaterial, by preliminarily drying the purge gas and feeding into theadsorbing tower, moisture is prevented from mixing into the adsorbingtower filled with silica gel, and the ozone adsorbing amount isincreased by utilizing the low temperature of the liquid oxygen.

[0007] Generally, the ozone adsorbing amount is larger as thetemperature is lower, but it is hard to cool lower than −60° C. unless aparticular refrigerating machine is used, and a large amount ofadsorbent is usually required for increasing the treated gas amount, andthe apparatus becomes larger in size, which causes to increase themanufacturing cost and running cost of the apparatus.

SUMMARY OF THE INVENTION

[0008] It is hence an object of the invention to solve the aboveproblems, and provide a method and apparatus for manufacturing highconcentration ozone gas capable of concentrating ozone efficiently, byusing a specific high silica ozone adsorbent excellent in ozoneadsorbing capability even in the presence of moisture, and applying thisadsorbent in a pressure swing adsorbing apparatus or a temperature swingadsorbing apparatus. Moreover, by combining a specific ozone generatingapparatus and the pressure swing adsorbing apparatus or temperatureswing adsorbing apparatus, it is also intended to provide a method andapparatus for manufacturing high concentration ozone further excellentin the ozone concentrating efficiency.

[0009] Invention of first group

[0010] The invention of a first group succeeded in solving the aboveproblems by employing the following constitution.

[0011] (1) A manufacturing method of high concentration ozone gas,characterized by employing a pressure swing adsorbing apparatus having aplurality of adsorbing layers filled with ozone adsorbent, adsorbingozone by feeding gas containing ozone at a relatively high pressure intothe adsorbing layers in the adsorbing process, and recoveringconcentrated ozone gas by setting the adsorbing layers of the desorbingprocess to a relatively low pressure, in which the ozone adsorbent is anadsorbent selected from the group consisting of high silica pentasylzeolite, dealuminized fogersite, and mesoporous silicate.

[0012] (2) A manufacturing method of high concentration ozone gasaccording to (1), in which the high silica pentasyl zeolite has theSiO₂/Al₂O₃ ratio of 70 or more, preferably 100 or more, dealuminizedfogersite has the SiO₂/Al₂O₃ ratio of 20 or more, preferably 50 or more,and mesoporous silicate has the SiO₂/Al₂O₃ ratio of 20 or more,preferably 50 or more.

[0013] (3) A manufacturing method of high concentration ozone gasaccording to (1) or (2), in which the adsorbing layers in the adsorbingprocess are held at temperature of −60° C. to 25° C.

[0014] (4) A manufacturing method of high concentration ozone gasaccording to any one of (1) to (3), in which the adsorbing pressure inthe adsorbing process is selected in a range of 1.05 to 5 atm, and thedesorbing pressure of the desorbing process is selected in a range of0.04 to 0.3 atm.

[0015] (5) A manufacturing method of high concentration ozone gasaccording to any one of (1) to (4), in which the changeover time of thepressure swing adsorbing apparatus is selected in a range of 1 to 10minutes.

[0016] (6) A manufacturing method of high concentration ozone gasaccording to any one of (1) to (5), in which part of the high pressureoxygen concentrated gas flowing out from the adsorbing layers in theadsorbing process is decompressed by a reducing valve, and is fed intothe adsorbing layers in the desorbing process to be purged.

[0017] (7) A manufacturing method of high concentration ozone gasaccording to (6), in which the purge rate in the purge operation isselected in a range of 1 to 2.

[0018] (8) A manufacturing method of high concentration ozone gasaccording to any one of (1) to (7), in which ozone is generated by usinga water electrolytic ozone generating apparatus of high pressure, thegas containing ozone is fed into the adsorbing layers in the adsorbingprocess of the pressure swing adsorbing apparatus, and part of the highpressure oxygen concentrated gas flowing out from the adsorbing layersin the adsorbing process is returned to the hydrogen electrode chamberof the water electrolytic ozone generating apparatus to depolarize theoxygen.

[0019] (9) A manufacturing method of high concentration ozone gasaccording to any one of (1) to (7), in which ozone is generated by usinga silent discharge ozone generating apparatus of high pressurespecification, the gas containing ozone is fed into the adsorbing layersin the adsorbing process of the pressure swing adsorbing apparatus, andpart of the high pressure oxygen concentrated gas flowing out from theadsorbing layers in the adsorbing process is returned to the materialside of the silent discharge ozone generating apparatus.

[0020] (10) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a pressure swing adsorbingapparatus having plural adsorbing layers filled with ozone adsorbent, inwhich the ozone generating apparatus is a water electrolytic ozonegenerating apparatus of high pressure, the ozone adsorbent is one or twoor more kinds of adsorbent selected from the group consisting of highsilica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, a compressor and a changeover valve are attached to a leadpipe for feeding gas containing ozone for connecting the ozonegenerating apparatus to the adsorbing layers in an adsorbing process, alead pipe for circulating oxygen concentrated gas flowing out from theadsorbing layers is connected to a hydrogen electrode chamber of thewater electrolytic ozone generating apparatus through the changeovervalve so as to depolarize the oxygen, a lead pipe for feeding purge gasbranched off the lead pipe for circulating oxygen concentrated gas isconnected to the adsorbing layers in a desorbing process through areducing valve and changeover valve, and a control device is providedfor changing over all the changeover valves to set the adsorbing layersalternately in the adsorbing process and desorbing process by connectinga lead pipe for recovering ozone to the adsorbing layers in thedesorbing process through a changeover valve to recover highconcentration ozone gas.

[0021] (11) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a pressure swing adsorbingapparatus having plural adsorbing layers filled with ozone adsorbent, inwhich the ozone generating apparatus is a silent discharge ozonegenerating apparatus of high pressure, the ozone adsorbent is one or twoor more kinds of adsorbent selected from the group consisting of highsilica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, a compressor and a changeover valve are attached to a leadpipe for feeding gas containing ozone for connecting the ozonegenerating apparatus to the adsorbing layers in an adsorbing process, alead pipe for circulating oxygen concentrated gas at a relatively highpressure flowing out from the adsorbing layers is connected to a leadpipe for feeding oxygen material of the silent discharge ozonegenerating apparatus, a lead pipe for feeding purge gas branched off thelead pipe for circulating oxygen concentrated gas is connected to theadsorbing layers in a desorbing process through a reducing valve andchangeover valve, and a control device is provided for changing over allthe changeover valves to set the adsorbing layers alternately in theadsorbing process and desorbing process by connecting a lead pipe forrecovering ozone to the adsorbing layers in the desorbing processthrough a changeover valve to recover high concentration ozone gas.

[0022] In this constitution, the invention of the first group canefficiently concentrate the ozone even in the presence of moisture, andthereby the manufacturing apparatus of high concentration ozone gas isreduced in size, and the manufacturing cost and running cost of theapparatus are substantially reduced. Moreover, when combined with thesilent discharge ozone generating apparatus of high pressure or waterelectrolytic ozone generating apparatus of high pressure, matching withthe pressure swing adsorbing apparatus is enhanced, and moreover byfeeding the concentrated oxygen gas in the adsorbing process into thehydrogen electrode of the water electrolytic ozone generating apparatus,the oxygen depolarizing action is promoted, and the power to be appliedcan be decreased.

[0023] Invention of second group

[0024] The invention of a second group succeeded in solving the aboveproblems by employing the following constitution.

[0025] (12) A manufacturing method of high concentration ozone gas,using two or more adsorbing layers filled with ozone adsorbent,employing a temperature swing adsorbing system for transferring theadsorbing layers from an adsorbing process at a relatively lowtemperature to a desorbing process at a relatively high temperature, andfurther returning to the adsorbing process, precooling the gascontaining ozone from an ozone generating apparatus and feeding into theadsorbing layers in the adsorbing process, discharging oxygenconcentrated gas at a relatively low temperature from the adsorbinglayers, passing purge gas at a relatively high temperature into theadsorbing layers in the desorbing process in an opposite direction ofthe gas flow in the adsorbing process, and recovering the concentratedozone gas continuously, in which the ozone adsorbent is one or two ormore kinds of adsorbent selected from the group consisting of highsilica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, and the gas containing ozone from the ozone generatingapparatus is cooled by the oxygen concentrated gas at a relatively lowtemperature flowing out from the adsorbing layers in the adsorbingprocess.

[0026] (13) A manufacturing method of high concentration ozone gasaccording to (12), in which the high silica pentasyl zeolite has theSiO₂/Al₂O₃ ratio of 70 or more, dealuminized fogersite has theSiO₂/Al₂O₃ ratio of 20 or more, and mesoporous silicate has theSiO₂/Al₂O₃ ratio of 20 or more.

[0027] (14) A manufacturing method of high concentration ozone gasaccording to (12) or (13), using three or more adsorbing layers andemploying a temperature swing adsorbing system for transferring theadsorbing layers from an adsorbing process at a relatively lowtemperature to a desorbing process at a relatively high temperature, andfurther returning to the adsorbing process through a cooling process, inwhich part of oxygen concentrated gas at a relatively low temperatureflowing out from the adsorbing process is fed into the adsorbing layersin the cooling process and is cooled.

[0028] (15) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (14), in which part of oxygenconcentrated gas at a relatively low temperature flowing out from theadsorbing process is heated to purge temperature, and is passed into theadsorbing layers in the desorbing process in an opposite direction ofthe gas flow in the adsorbing process, and the ozone is heated, purgedand desorbed.

[0029] (16) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (15), in which purge gas suited to thepurpose of use of the high concentration ozone gas is heated to purgetemperature, and is passed into the adsorbing layers in the desorbingprocess in an opposite direction of the gas flow in the adsorbingprocess, and the ozone is heated, purged and desorbed.

[0030] (17) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (16), in which the purge rate in thepurge operation is selected in a range of 1 to 2.

[0031] (18) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (17), in which the adsorbing temperatureof the adsorbing process is selected in a range of −100° C. to −30° C.,preferably in a range of −60° C. to −30° C., and the desorbingtemperature of the desorbing process is selected in a range of 0° C. to50° C.

[0032] (19) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (18), in which the adsorbing pressure ofthe adsorbing process is selected in a range of 1 to 4 atm.

[0033] (20) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (19), in which the changeover time ofthe temperature swing adsorbing system is selected in a range of 10 to60 minutes.

[0034] (21) A manufacturing method of high concentration ozone gasaccording to any one of (12) to (20), using a water electrolytic ozonegenerating apparatus as the ozone generating apparatus, in which part ofthe oxygen concentrated gas flowing out from the adsorbing layers in theadsorbing process is returned to the hydrogen electrode chamber of thewater electrolytic ozone generating apparatus to depolarize the oxygen.

[0035] (22) A manufacturing method of high concentration ozone gasaccording to anyone of (12) to (20), using a silent discharge ozonegenerating apparatus as the ozone generating apparatus, in which part ofthe oxygen concentrated gas flowing out from the adsorbing layers in theadsorbing process is returned to the oxygen material side of the silentdischarge ozone generating apparatus.

[0036] (23) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a temperature swingadsorbing apparatus having plural adsorbing layers filled with ozoneadsorbent, in which the ozone generating apparatus is a waterelectrolytic ozone generating apparatus, the ozone adsorbent is one ortwo or more kinds of adsorbent selected from the group consisting ofhigh silica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, a heat exchanger, a cooler and a changeover valve are attachedto a lead pipe for feeding gas containing ozone for connecting the ozonegenerating apparatus to the adsorbing layers in an adsorbing process, alead pipe for circulating oxygen concentrated gas at a relatively lowtemperature flowing out from the adsorbing layers is connected to theheat exchanger through the changeover valve, the gas containing ozone isprecooled by the oxygen concentrated gas at relatively low temperaturein the heat exchanger, the outlet side of the oxygen concentrated gas ata relatively low temperature of the heat exchanger is connected to ahydrogen electrode chamber of the water electrolytic ozone generatingapparatus through a lead pipe, the oxygen concentrated gas at arelatively low temperature is supplied into the hydrogen electrodechamber to encourage the oxygen depolarization action, a lead pipe forfeeding purge gas is branched off from the lead pipe for circulating theoxygen concentrated gas at a relatively low temperature, and isconnected to the adsorbing layers in a desorbing process, a heater and achangeover valve are attached to the lead pipe for feeding purge gas tosupply the oxygen concentrated gas at a relatively low temperature tothe adsorbing layers as heating purge gas, the other end of theadsorbing layers in the desorbing process is connected to a lead pipefor recovering high concentration ozone gas through the changeovervalve, and all the changeover vales are changed over simultaneously touse the adsorbing layers alternately in the adsorbing process anddesorbing process.

[0037] (24) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a merry-go-round typetemperature swing adsorbing apparatus having three or more adsorbinglayers filled with ozone adsorbent, in which the ozone generatingapparatus is a water electrolytic ozone generating apparatus, the ozoneadsorbent is one or two or more kinds of adsorbent selected from thegroup consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate, a lead pipe for feeding gascontaining ozone from the ozone generating apparatus and a lead pipe forcirculating oxygen concentrated gas can be connected before and afterthe adsorbing layers in an adsorbing process, a lead pipe for feedingheating purge gas and a lead pipe for recovering high concentrationozone gas can be connected before and after the adsorbing layers in adesorbing process, a lead pipe for feeding cooling gas branched off fromthe lead pipe for circulating the oxygen concentrated gas and a leadpipe for recovery of the cooling gas can be connected before and afterthe adsorbing layers in a cooling process, the adsorbing process,desorbing process and cooling process are transferred sequentially byrotating the merry-go-round composed of the adsorbing layers, a heatexchanger and a cooler are attached to the lead pipe for feeding gascontaining oxygen, the lead pipe for circulating oxygen concentrated gasis connected to the heat exchanger, the gas containing ozone isprecooled by the oxygen concentrated gas at relatively low temperatureflowing out from the adsorbing layers in the adsorbing process, theoutlet side of the oxygen concentrated gas at a relatively lowtemperature of the heat exchanger is connected to a hydrogen electrodechamber of the water electrolytic ozone generating apparatus through alead pipe, and the oxygen concentrated gas at a relatively lowtemperature is supplied into the hydrogen electrode chamber to encouragethe oxygen depolarization action.

[0038] (25) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a temperature swingadsorbing apparatus having plural adsorbing layers filled with ozoneadsorbent, in which the ozone generating apparatus is a silent dischargeozone generating apparatus, the ozone adsorbent is one or two or morekinds of adsorbent selected from the group consisting of high silicapentasyl zeolite, dealuminized fogersite, and mesoporous silicate, aheat exchanger, a cooler and a changeover valve are attached to a leadpipe for feeding gas containing oxygen for connecting the ozonegenerating apparatus to the adsorbing layers in an adsorbing process, alead pipe for circulating oxygen concentrated gas at a relatively lowtemperature flowing out from the adsorbing layers is connected to theheat exchanger through a changeover valve, the gas containing ozone isprecooled by the oxygen concentrated gas at a relatively low temperaturein the heat exchanger, the outlet side of the oxygen concentrated gas ata relatively low temperature of the heat exchanger is connected to theoxygen material supply side of the silent discharge ozone generatingapparatus through a lead pipe so as to recycle the oxygen concentratedgas, a lead pipe for feeding purge gas is branched off from the leadpipe for circulating oxygen concentrated gas at a relatively lowtemperature and is connected to the adsorbing layers in a desorbingprocess, a heater and a changeover valve are attached to the lead pipefor feeding purge gas so that the oxygen concentrated gas at arelatively low temperature may be supplied to the adsorbing layers asheating purge gas, other end of the adsorbing layers in the desorbingprocess is connected to a lead pipe for recovering high concentrationozone gas through the changeover valve, and all the changeover valvesare changed over simultaneously to use the adsorbing layers alternatelyin the adsorbing process and desorbing process.

[0039] (26) A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a merry-go-round typetemperature swing adsorbing apparatus having three or more adsorbinglayers filled with ozone adsorbent, in which the ozone generatingapparatus is a silent discharge ozone generating apparatus, the ozoneadsorbent is one or two or more kinds of adsorbent selected from thegroup consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate, a lead pipe for feeding gascontaining ozone from the ozone generating apparatus and a lead pipe forcirculating oxygen concentrated gas can be connected before and afterthe adsorbing layers in an adsorbing process, a lead pipe for feedingheating purge gas and a lead pipe for recovering high concentrationozone gas can be connected before and after the adsorbing layers in adesorbing process, a lead pipe for feeding cooling gas branched off fromthe lead pipe for circulating the oxygen concentrated gas and a leadpipe for recovery of the cooling gas can be connected before and afterthe adsorbing layers in a cooling process, the adsorbing process,desorbing process and cooling process are transferred sequentially byrotating the merry-go-round composed of the adsorbing layers, a heatexchanger and a cooler are attached to the lead pipe for feeding gascontaining oxygen, the lead pipe for circulating oxygen concentrated gasis connected to the heat exchanger, the gas containing ozone isprecooled by the oxygen concentrated gas at relatively low temperatureflowing out from the adsorbing layers in the adsorbing process, and isfurther cooled to the adsorbing temperature by the cooler, and theoutlet side of the oxygen concentrated gas at a relatively lowtemperature of the heat exchanger is connected to oxygen material supplyside of the silent discharge ozone generating apparatus through a leadpipe so that the oxygen concentrated has can be recycled.

[0040] In this constitution, the invention of the second group canefficiently concentrate the oxygen even in the presence of moisture, andthereby the manufacturing apparatus of high concentration ozone gas isreduced in size, and the manufacturing cost and running cost of theapparatus are substantially reduced. Moreover, by feeding theconcentrated oxygen gas flowing out from the adsorbing process into thehydrogen electrode of the water electrolytic ozone generating apparatus,the oxygen depolarizing action is promoted, and the power to be appliedcan be decreased. Besides, by returning the concentrated oxygen gasflowing out from the adsorbing process to the oxygen material side ofthe silent discharge ozone generating apparatus, the concentrated oxygencan be utilized effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041]FIG. 1 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone in a first group of the invention, in which awater electrolytic ozone generating apparatus and a pressure swingadsorbing apparatus for concentrating ozone are combined;

[0042]FIG. 2 is a conceptual diagram of other manufacturing apparatus ofhigh concentration ozone in the first group of the invention, in which asilent discharge ozone generating apparatus and a pressure swingadsorbing apparatus for concentrating ozone are combined;

[0043]FIG. 3 is a graph comparing the ozone concentrating rate byfilling the adsorbing tower of the apparatus in FIG. 1 with mesoporoussilicate, dealuminized fogersite, and silica gel;

[0044]FIG. 4 is a graph showing the treating amount of gas containingozone by changing the cycle time, with the adsorbing tower of theapparatus in FIG. 1 filled with mesoporous silicate;

[0045]FIG. 5 is a graph showing the ozone concentration rate by changingthe desorbing pressure, with the adsorbing tower of the apparatus inFIG. 1 filled with mesoporous silicate;

[0046]FIG. 6 is a graph showing the ozone concentration rate by changingthe desorbing pressure, with the adsorbing tower of the apparatus inFIG. 1 filled with mesoporous silicate;

[0047]FIG. 7 is a graph showing the ozone concentration rate by changingthe purge rate, with the adsorbing tower of the apparatus in FIG. 1filled with mesoporous silicate;

[0048]FIG. 8 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone in a second group of the invention, in which awater electrolytic ozone generating apparatus and a temperature swingadsorbing apparatus for concentrating ozone are combined;

[0049]FIG. 9 is a conceptual diagram of other manufacturing apparatus ofhigh concentration ozone in the second group of the invention, in whicha silent discharge ozone generating apparatus and a temperature swingadsorbing apparatus for concentrating ozone are combined;

[0050]FIG. 10 is a conceptual diagram of a different manufacturingapparatus of high concentration ozone in the second group of theinvention, in which a water electrolytic ozone generating apparatus anda merry-go-round type temperature swing adsorbing apparatus forconcentrating ozone are combined;

[0051]FIG. 11 is a conceptual diagram of other different manufacturingapparatus of high concentration ozone in the second group of theinvention, in which a silent discharge ozone generating apparatus and amerry-go-round type temperature swing adsorbing apparatus forconcentrating ozone are combined;

[0052]FIG. 12 is a graph comparing the ozone concentrating rate byfilling the adsorbing tower of the apparatus in FIG. 8 with high silicapentasyl zeolite, dealuminized fogersite, and mesoporous silicate, andsilica gel;

[0053]FIG. 13 is a graph showing the treating amount of gas containingozone by changing the cycle time, with the adsorbing tower of theapparatus in FIG. 8 filled with mesoporous silicate;

[0054]FIG. 14 is a graph showing the ozone concentration rate bychanging the desorbing temperature, with the adsorbing tower of theapparatus in FIG. 8 filled with mesoporous silicate; and

[0055]FIG. 15 is a conceptual diagram of a conventional ozoneconcentrating apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] The present inventors discovered that high silica ozoneadsorbents, in particular, high silica pentasyl zeolite, dealuminizedfogersite such as ultra-stable Y type zeolite (USY), and mesoporoussilicate such as MCM-41, FSM-16, low temperature acidic syntheticmesoporous silicate having tetra ethoxy silane as silica source and lowtemperature acidic synthetic mesoporous silicate having low molecularsilicic acid as silica source, have an excellent ozone adsorbingcapability even in the presence of moisture, and attempted to apply themin the pressure swing adsorbing apparatus for concentrating ozone andsucceeded in manufacturing high concentration ozone gas efficiently,thereby enabling to reduce the size of the manufacturing apparatus ofhigh concentration ozone gas, and substantially reduce the manufacturingcost and running cost of the apparatus.

[0057] The high silica pentasyl zeolite used in the invention has anexcellent ozone adsorbing capability, and it can be obtained byhydrothermal synthesis at 150 to 180° C., by using sodium silicate orfumed silica as silica source, and tetrapropyl ammonium bromide asorganic template. The high silica pentasyl zeolite of the presentinvention is preferred to have the SiO₂/Al₂O₃ ratio of 70 or more,preferably 100 or more. Although the high silica pentasyl zeolite itselfhas been known, it was first discovered by the present inventors that ithas such ozone adsorbing capability as mentioned above.

[0058] The dealuminized fogersite used in the present invention has anexcellent ozone adsorbing capability even in the presence of moisture,and by treating Na—Y type zeolite having the SiO₂/Al₂O₃ ratio of about 5in ammonia water, it can be manufactured by removing the majority of Alof the zeolite skeleton. The dealuminized fogersite of the presentinvention is preferred to have the SiO₂/Al₂O₃ ratio of 20 or more,preferably 50 or more. Although the dealuminized fogersite itself hasbeen known, it was first discovered by the present inventors that it hassuch ozone adsorbing capability as mentioned above.

[0059] The mesoporous silicate used in the present invention is a poroussubstance of silica compound having meso pores of 10 to 1000 Å, and hasan excellent ozone adsorbing capability even in the presence ofmoisture. The mesoporous silicate of the present invention can bemanufactured in various methods, and its SiO₂/Al₂O₃ratio is preferred tobe 20 or more, preferably 50 or more. Although the mesoporous silicateitself has been known as mentioned below, it was first discovered by thepresent inventors that it has such ozone adsorbing capability asmentioned above.

[0060] For example, MCM-41 was developed by Mobil, which is a mesoporoussilicate with the specific surface area of about 1600 m²/g andSiO₂/Al₂O₃ ratio of about 1000, obtained by hydrothermal synthesis attemperature of 140° C. and pH 13.5, by using water glass or sodiumsilicate as silica source, and cationic surface active agent (with 8 ormore carbon atoms) as organic template.

[0061] Still more, FSM-16 is a mesoporous silicate with the SiO₂/Al₂O₃ratio of about 1000 obtained by intercalation of cationic surface activeagent in Kanemite developed by Kuroda, Inada, et al., and has astructure similar to that of MCM-41.

[0062] Low temperature mesoporous silicate (1) is obtained by a methodproposed by Stucky et al., and is synthesized at pH 1 or less at roomtemperature, using tetraethoxy silane (TEOS) as silica source andcationic surface active agent as organic template. Low temperaturemesoporous silicate (2) is obtained by a method developed by the presentinventors, and is synthesized at pH 1 or less at room temperature, usingcondensation-polymerized silica-free silicic acid as silica source andcationic surface active agent as organic template. These low temperaturemesoporous silicates may be manufactured in a wide range, depending onthe manufacturing conditions, ranging from the SiO₂/Al₂O₃ ratio of 10 toa substantially SiO2 only compound.

[0063] Invention of first group

[0064] The invention of a first group provides a method and apparatusfor manufacturing high concentration ozone gas characterized bymanufacturing gas containing ozone by an ozone generating apparatus suchas silent discharge apparatus or water electrolytic apparatus, usingplural adsorbing layers filled with specific high silica ozoneadsorbent, adsorbing ozone by feeding the gas containing ozone into theadsorbing layers in an adsorbing process at a relatively high pressure,while desorbing ozone by setting the adsorbing layers in a desorbingprocess at a relatively low pressure, feeding purge gas in the desorbingprocess if necessary, and employing a pressure swing adsorbing systemfor alternately changing over the adsorbing layers between the adsorbingprocess at a relatively high pressure and the desorbing process at arelatively low pressure in a short time, thereby concentrating theozone.

[0065] In the invention of the first group, by using a silent dischargeapparatus of high pressure as the ozone generating apparatus, andreturning the high pressure oxygen concentrated gas flowing out from theadsorbing process of the pressure swing adsorbing apparatus forconcentrating ozone to the material side of the silent discharge ozonegenerating apparatus to be used as oxygen material, the gas containingozone flowing out from the silent discharge apparatus can be recoveredat high pressure, and the load of the compressor for feeding to thepressure swing adsorbing apparatus can be reduced. As the oxygenmaterial gas to be supplied into the silent discharge ozone generatingapparatus, the high pressure oxygen concentrated gas manufactured in thepressure swing adsorbing apparatus for concentrating oxygen can be used,which is effective for efficiency and performance of the entireapparatus.

[0066] By using a water electrolytic apparatus of high pressure as theozone generating apparatus, and returning part of the oxygenconcentrated gas flowing out from the adsorbing process of the pressureswing adsorbing apparatus for concentrating ozone into the hydrogenelectrode chamber of the water electrolytic apparatus to react withhydrogen, it is advantageous because the electric power to be applied inthe water electrolytic apparatus can be reduced by the oxygendepolarizing action.

[0067] The adsorbing tower transferred to the desorbing process of thepressure swing adsorbing apparatus for concentrating ozone recoversozone concentrated gas by setting to a relatively low desorbing pressureby using, for example, a decompression pump, but it is also possible topromote desorption by purging by feeding part of the high pressureoxygen concentrated gas flowing out from the desorbing process into theadsorbing layers in the desorbing process through a reducing valve. Atthis time, if necessary, a heat exchanger or a heater may be attached tothe downstream side of the reducing valve to heat the oxygenconcentrated gas to a temperature suited to purging.

[0068]FIG. 1 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone combining a water electrolytic ozone generatingapparatus 1 of high pressure, and a two-tower type pressure swingadsorbing apparatus for concentrating ozone. Adsorbing towers 6 and 7are filled with ozone adsorbent of one or two or more kinds of adsorbentselected from the group consisting of high silica pentasyl zeolite,dealuminized fogersite, and mesoporous silicate. The water electrolyticozone generating apparatus 1 consists of an ozone electrode chamber 3such as PbO₂, and a hydrogen electrode chamber 4 such as Pt, with an ionexchange film 2 placed between them, and by connecting a direct-currentpower source 5, electrons are supplied, and ozone is generated in theozone electrode chamber 3 while hydrogen is generated in the hydrogenelectrode chamber 4.

[0069]FIG. 1 shows the state of holding the adsorbing tower 6 in anadsorbing process and the adsorbing tower 7 in a desorbing process, byopening changeover valves 10, 13, 17, 21, and closing changeover valves11, 14, 16, 20, and by opening and closing the changeover valvesreversely, the process can be changed over from absorption todesorption, and from desorption to adsorption. The gas containing ozonefrom the ozone generating apparatus 1 is pressurized to an adsorbingpressure by a compressor 9 provided on a lead pipe 8, and is suppliedinto the adsorbing tower 6 in the adsorbing process to adsorb ozone onthe adsorbent, and the oxygen concentrated gas flowing out from theadsorbing tower 6 is supplied into the hydrogen electrode chamber 4 ofthe water electrolytic ozone generating apparatus 1 through a lead pipe12, and the power consumption of the ozone generating apparatus is savedby the oxygen depolarizing action. By using the water electrolytic ozonegenerating apparatus of high pressure, since the load of the compressorfor feeding gas containing ozone to the pressure swing adsorbingapparatus can be reduced, the efficiency and performance of the entireapparatus can be enhanced.

[0070] On the other hand, the ozone recovering system is held at adesorbing pressure, and by opening the changeover valve 17 of a leadpipe 15, ozone is recovered by decompressed desorption from theadsorbing tower 7 in the desorbing process. Part of the high pressureoxygen concentrated gas flowing out from the adsorbing tower 6 in thedesorbing process is reduced to a desorbing pressure by a reducing valve19 provided in a lead pipe 18 for feeding purge gas branched off fromthe lead pipe 12, and supplied into the adsorbing tower 7 in thedesorbing process to purge by back wash, so that the desorption may bepromoted. When the purge gas is used in a large volume, the ozoneconcentration is lowered by the corresponding portion. The purge rate ispreferably in a range of 1 to 2, more preferably in a range of 1.2 to1.5 (see FIG. 7).

[0071]FIG. 2 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone using a silent discharge ozone generatingapparatus 22 of high pressure, instead of the water electrolytic ozonegenerating apparatus of high pressure in the manufacturing apparatus ofhigh concentration ozone in FIG. 1, and the structure of the pressureswing adsorbing apparatus is same as in the apparatus in FIG. 1, and thereference numerals of the apparatus are hence matched. In FIG. 2, apressure swing adsorbing apparatus 23 for concentration oxygen isattached before the silent discharge ozone generating apparatus 22. Thispressure swing adsorbing apparatus 23 for concentrating oxygen is notessential, but is effective for enhancing the efficiency and performanceof the entire apparatus.

[0072] The adsorption cycle of the pressure swing adsorbing apparatusfor concentrating ozone is same as in the case of FIG. 1, but part ofthe high pressure oxygen concentrated gas flowing out from the adsorbingtower 6 in the adsorbing process is, if necessary, returned to the leadpipe for feeding oxygen material of the silent discharge ozonegenerating apparatus 22 through the lead pipe 12, so that the oxygenconcentrated gas can be used effectively. Furthermore, by using thesilent discharge ozone generating apparatus of high pressure, the loadof the compressor 9 for feeding gas containing ozone to the pressureswing adsorbing apparatus can be reduced, and it is effective forenhancing the efficiency and performance of the entire apparatus.

[0073] Invention of second group

[0074] The invention of a second group provides a method and apparatusfor manufacturing high concentration ozone gas, characterized by usingtwo or more adsorbing layers filled with ozone adsorbent, employing atemperature swing adsorbing system for transferring the adsorbing layersfrom an adsorbing process at a relatively low temperature to a desorbingprocess at a relatively high temperature, and further returning to theadsorbing process, precooling gas containing ozone from an ozonegenerating apparatus and feeding into the adsorbing layers in theadsorbing process, discharging oxygen concentrated gas at a relativelylow temperature from the adsorbing layers, passing purge gas at arelatively high temperature into the adsorbing layers in the desorbingprocess in an opposite direction of the gas flow in the adsorbingprocess, and recovering the concentrated ozone gas continuously, inwhich the ozone adsorbent is a specific high silica ozone adsorbentexcellent in ozone adsorbing capability even in the presence ofmoisture.

[0075] In the invention of the second group, it is preferred to utilizethe cooling energy effectively by cooling the gas containing ozone fromthe ozone generating apparatus by oxygen concentrated gas at arelatively low temperature flowing out from the adsorption process ofthe temperature swing adsorbing apparatus for concentrating ozone.

[0076] When using a water electrolytic ozone generating apparatus as theozone generating apparatus, it is preferred to reduce the electric powerto be applied by the oxygen depolarizing action of the waterelectrolytic apparatus by returning part of the oxygen concentrated gasflowing out from the adsorbing process of the temperature swingadsorbing apparatus for concentrating ozone into the hydrogen electrodechamber of the water electrolytic ozone generating apparatus.

[0077] Further, by using a silent discharge apparatus as the ozonegenerating apparatus, it is preferred to utilize the oxygen effectivelyby returning the oxygen concentrated gas at a relatively low temperatureflowing out from the adsorbing process of the temperature swingadsorbing apparatus for concentrating ozone to the oxygen material sideof the silent discharge ozone generating apparatus.

[0078]FIG. 8 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone combining a water electrolytic ozone generatingapparatus 101, and a two-tower type temperature swing adsorbingapparatus for concentrating ozone. Adsorbing towers 108 and 109 arefilled with ozone adsorbent of one or two or more kinds of adsorbentselected from the group consisting of high silica pentasyl zeolite,dealuminized fogersite, and mesoporous silicate. The ozone adsorbent maybe used also by forming in a honeycomb structure. The water electrolyticozone generating apparatus 101 consists of an ozone electrode chamber103 such as PbO₂, and a hydrogen electrode chamber 104 such as Pt, withan ion exchange film 102 placed between them, and by connecting adirect-current power source 105, electrons are supplied, and ozone isgenerated in the ozone electrode chamber 103 while hydrogen is generatedin the hydrogen electrode chamber 104.

[0079] In the apparatus shown in FIG. 8, by opening changeover valves113, 116, 122, 125, and closing changeover valves 114, 117, 121, 124,same as in FIG. 1, the adsorbing tower 108 is set in an adsorbingprocess and the adsorbing tower 109 in a desorbing process, and byopening and closing the changeover valves reversely after the processes,the adsorbing tower 108 is transferred from absorption process todesorption process, and the adsorbing tower 109, from desorption processto adsorption process. A heat exchanger 112 and a cooler 111 areattached to a lead pipe 110 for feeding gas containing ozone forconnecting the ozone electrode chamber 103 and adsorbing tower 108 ofthe water electrolytic ozone generating apparatus 101, and the gascontaining ozone is cooled to an adsorbing temperature, and is suppliedinto the adsorbing tower 108 in the adsorbing process to adsorb ozone,and the oxygen concentrated gas at a relatively low temperature flowingout from the adsorbing tower 108 is sent into the heat exchanger 112through a lead pipe 115 to precool the gas containing ozone. The oxygenconcentrated gas at a relatively low temperature flowing out from theheat exchanger 112 is fed into the hydrogen electrode chamber 104 of thewater electrolytic ozone generating apparatus 101 to react withhydrogen, and the electric power to be applied in the water electrolyticozone generating apparatus 101 is decreased by the oxygen depolarizingaction. Reference numeral 106 is a lead pipe for feeding water, and 107is a lead pipe for discharging hydrogen from the hydrogen electrodechamber. Reference numeral 105 is a direct-current power source.

[0080] On the other hand, part of the oxygen concentrated gas at arelatively low temperature flowing out from the adsorbing tower 108 issupplied into the adsorbing tower 109 in the desorbing process to heat,purge and desorb the ozone through a lead pipe 118 and, if necessary, areducing valve 119 and a heater 120, and high concentration ozone gas isrecovered from a lead pipe 123. At this time, when the purge gas is usedin a large volume, the ozone concentration is lowered by thecorresponding portion. The purge rate is preferably in a range of 1 to2. As the purge gas, instead of the oxygen concentrated gas, nitrogen,dry air, argon, helium or the like may be used, and supplied fromoutside.

[0081]FIG. 9 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone using a silent discharge ozone generatingapparatus 126, instead of the water electrolytic ozone generatingapparatus in the manufacturing apparatus of high concentration ozone inFIG. 8. The parts common to the apparatus in FIG. 8 are identified withsame reference numerals. In FIG. 9, a temperature swing adsorbingapparatus 127 for concentration oxygen is attached before the silentdischarge ozone generating apparatus 126, but this adsorbing apparatusis not essential. However, considering matching of the entire apparatus,it is preferred to employ it. In the apparatus in FIG. 9, oxygenmaterial, for example, air is supplied into the temperature swingadsorbing apparatus 127 for concentrating oxygen through a lead pipe128, and the concentrated oxygen gas is discharged from a lead pipe 129,and is supplied into the silent discharge ozone generating apparatus126. The adsorption cycle of the temperature swing adsorbing apparatusfor concentrating ozone is same as in the case of FIG. 8, but part ofthe oxygen concentrated gas flowing out from the adsorbing tower in theadsorbing process is preferred to be returned to the oxygen materialside of the silent discharge ozone generating apparatus 126 through alead pipe 130 by way of the heat exchanger 112 for precooling the gascontaining ozone, so that the oxygen can be utilized effectively.

[0082]FIG. 10 is a conceptual diagram of a manufacturing apparatus ofhigh concentration ozone combining a water electrolytic ozone generatingapparatus 101 and a merry-go-round type temperature swing adsorbingapparatus for concentrating ozone consisting of adsorbing layers 131 to134. In the state shown in FIG. 10, the adsorbing layers 131 and 132 arein an adsorbing process, the adsorbing layer 133 in a desorbing process,and the adsorbing layer 134 in a cooling process following the desorbingprocess. The adsorbing layers may be further divided depending on thenecessity, and plural adsorbing layers may be used according to thecycle time of each process. The merry-go-round of the adsorbing layersis rotated in the arrow direction, and the processes can be transferredsequentially without using changeover valve. The gas containing ozonegenerated in the ozone electrode chamber 103 of the water electrolyticozone generating apparatus 101 is cooled to an adsorbing temperature bythe heat exchanger 112 and cooler 111 of the lead pipe 110, and issupplied into the adsorbing layers 131 and 132 in the adsorbing processto adsorb ozone, and the oxygen concentrated gas at a relatively lowtemperature flowing out from these adsorbing layers is supplied into theheat exchanger through lead pipes 137, 138, 139, and 140, and furtherinto the hydrogen electrode chamber 104 of the water electrolytic ozonegenerating apparatus 101, thereby depolarizing the oxygen.

[0083] Part of oxygen concentrated gas at a relatively low temperatureflowing out from the adsorbing layers 131 and 132 in the adsorbingprocess is supplied into the adsorbing layer 134 in the cooling processthrough a lead pipe 141 branched off from the lead pipe 139, and coolsthe adsorbing layer 134 after finishing the desorbing process. When theoxygen concentrated gas flowing out from this adsorbing layer 134 isused as purge gas, a heater 143 is attached to a lead pipe 142, andafter heating to a desorbing temperature, it is supplied into theadsorbing layer 133 in the desorbing process to heat, purge and desorb.When a purge gas for desorbing is used separately, the purge gas issupplied from a lead pipe 144, and after heating to a desorbingtemperature by a heater 145, it is similarly supplied into the adsorbinglayer 133, and the desorbed high concentration ozone gas is sent intothe recovery system through a lead pipe 146.

[0084]FIG. 11 is similar to the manufacturing apparatus of highconcentration ozone in FIG. 10, using a silent discharge ozonegenerating apparatus 126, instead of the water electrolytic ozonegenerating apparatus, and the parts common to the apparatus in FIG. 10are identified with same reference numerals. In the apparatus in FIG.11, a temperature swing adsorbing apparatus 127 for concentrating oxygenis attached before the silent discharge ozone generating apparatus 126,and oxygen material, for example, air is supplied into the temperatureswing adsorbing apparatus 127 for concentrating oxygen through a leadpipe 128 to concentrate the oxygen, and is supplied into the silentdischarge ozone generating apparatus 126 through a lead pipe 129, but inthe invention, the temperature swing adsorbing apparatus 127 forconcentrating oxygen is not essential. The adsorbing operation of themerry-go-round type temperature swing adsorbing apparatus forconcentrating ozone is same as in the apparatus in FIG. 10. The oxygenconcentrated gas at a relatively low temperature flowing out from theadsorbing layers 131 and 132 in the adsorbing process precools, same asin the apparatus shown in FIG. 10, the gas containing ozone by the heatexchanger 112, and is returned to the oxygen material side of the silentdischarge ozone generating apparatus 126 through a lead pipe 130, sothat the concentrated oxygen gas can be utilized effectively.

EXAMPLES Example 1

[0085] The adsorbing towers of the manufacturing apparatus of highconcentration ozone in FIG. 1 were filled with the ozone adsorbentsaccording to the present invention, that is, high silica pentasylzeolite, dealuminized fogersite, and mesoporous silicate, and aconventional ozone adsorbent, silica gel, and the ozone concentrationrate were measured, and the ozone adsorbing capabilities were compared.Herein, the adsorbing towers were filled with 5 kg each of the highsilica pentasyl zeolite with the SiO₂/Al₂O₃ ratio of 100, dealuminizedfogersite with the SiO₂/Al₂O₃ ratio of 70, mesoporous silicate with theSiO₂/Al₂O₃ ratio of 1000, and commercial silica gel.

[0086] In the water electrolytic ozone generating apparatus, ozone gas(ozone concentration 10%) composed of 10 vol. % of O₃, 87 vol. % of O₂,and 3 vol. % of H₂O was generated, and pressurized to 1.1 atm by acompressor, and supplied into the adsorbing tower in the adsorbingprocess at a gas flow rate of 15 m³ N/h, and ozone was adsorbed. On theother hand, the adsorbing tower in the desorbing process wasdecompressed by 0.1 atm by a decompression pump, and the ozone wasdesorbed and recovered without purging. The adsorbing temperature wasset at −60° C., −30° C. and 25° C., and the ozone concentration wasexperimented. In the desorbing process, the temperature of the adsorbingtower was not particularly controlled. The changeover time of theadsorbing process and desorbing process, that is, the cycle time was setat 3 minutes.

[0087] The ozone concentration of the obtained ozone concentrated gaswas measured, and compared with the ozone concentration of the gasproduced in the water electrolytic ozone generating apparatus, and theozone concentration rate was determined, and the adsorbing temperatureand the ozone concentration rate are comparatively shown in FIG. 3. Asclear from this diagram, as compared with the silica gel, it is knownthat the dealuminized fogersite and mesoporous silicate show a verylarge ozone adsorbing capability. Incidentally, the small ozoneadsorbing capability of silica gel seems to be due to the effect ofmoisture in the gas containing ozone.

[0088] Considering the capacity of cooler for general use, the adsorbingtemperature is preferred to be set at −60° C. or higher, and alsoconsidering the use of recovered ozone gas, the adsorbing temperature ispreferred to be set at room temperature of 25° C. or less.

Example 2

[0089] Using the mesoporous silicate having the largest ozone adsorbingcapability, and changing the cycle time from 0.5 min to 3 min, thetreating capacity of gas containing ozone was investigated (m³ N/h/l tonof adsorbent). In this experiment, using the same apparatus in FIG. 1 asin Example 1, the adsorbing temperature was set at −60° C. and 25° C.,the adsorbing pressure was changed to 1.05 atm, and the desorbingpressure to 0.05 atm, and the ozone concentration was experimented sameas in Example 1 in all other conditions. Results are shown in FIG. 4.

[0090] The ozone concentration of the gas containing ozone from thewater electrolytic ozone generating apparatus was 10 vol. %, but theozone concentration of the gas recovered in the desorbing process was 50vol. % (ozone concentration rate 5), and the ozone recovery rate was95%. As clear from the diagram, the treating capacity is larger as theadsorbing temperature is lower and the cycle time is shorter, and aspecified treating capacity is obtained by a relatively small amount ofadsorbent, and hence it is easy to reduce the size of the adsorbingtower, but a larger cooling energy is required. On the other hand, asthe adsorbing temperature is approaching the room temperature, thetreating capacity is smaller, but less cooling energy is needed. Nearthe room temperature, moreover, the effect of cycle time is smaller.

Example 3

[0091] Using the mesoporous silicate same as in Example 2, and changingthe desorbing pressure from 0.04 atm to 0.3 atom, the ozoneconcentration rate was investigated, and the dependence of desorbingpressure was studied. In this experiment, too, using the same apparatusin FIG. 1 as in Example 1, the ozone concentration was experimented sameas in Example 1, except that the adsorbing temperature was set at −60°C. and 25° C. and that the adsorbing pressure was fixed at 1.05 atm.Results are shown in FIG. 5.

[0092] As clear from FIG. 5, at the desorbing pressure of 0.3 atm, therewas almost no difference in the ozone concentration rate between theadsorbing temperature of −60° C. and 25° C., but as the desorbingpressure was lower, the difference in the ozone concentration rate beganto increase, and at 0.04 atm, the difference in the ozone concentrationrate due to difference in the adsorbing temperature was a difference of5 times and 4 times.

Example 4

[0093] Using the mesoporous silicate same as in Example 3, fixing thedesorbing pressure at 0.1 atom, and changing the adsorbing pressure from1 to 5 atm, the ozone concentration rate was investigated, and thedependence of adsorbing pressure was studied. In this experiment, too,using the same apparatus in FIG. 1 as in Example 1, the ozoneconcentration was experimented same as in Example 1, except that theadsorbing temperature was set at −65° C. and 25° C. Results are shown inFIG. 6.

[0094] As clear from FIG. 6, the ozone concentration rate elevatedalmost proportionally as the adsorbing pressure climbed up, and betweenthe adsorbing temperature of −60° C. and 25° C., the former was higherin the ozone concentration rate by about 0.5 times. Hence, the preferredadsorbing pressure was set in a range of 1.05 to 5 atm.

Example 5

[0095] Using the mesoporous silicate same as in Example 3, the ozoneconcentration rate was investigated and the dependence of purge rate wasstudied, by fixing the adsorbing pressure at 1.05 atm and the desorbingpressure at 0.05 atm, setting the adsorbing temperature at 25° C., notparticularly controlling the temperature of the adsorbing tower in thedesorbing process, feeding part of oxygen concentrated gas flowing outfrom the adsorbing tower in the adsorbing process as purge gas into theadsorbing tower in the desorbing process through a reducing valve,adjusting the reducing valve and changing the purge rate in a range of0.9 to 2. Results are shown in FIG. 7.

[0096] As clear from FIG. 7, by feeding the purge gas, the ozoneconcentration rate can be heightened, but as the purge gas volume isincreased, the ozone concentration in the recovered gas declines. Hence,in order to maintain the ozone concentration rate at 2 times or more, itis preferred to control the purge rate in a range of 1 to 2.

Example 6

[0097] The adsorbing towers of the manufacturing apparatus of highconcentration ozone in FIG. 8 were filled with the ozone adsorbents ofthe present invention, that is, high silica pentasyl zeolite,dealuminized fogersite, and mesoporous silicate, and a conventionalozone adsorbent, silica gel, and the ozone concentration rate weremeasured, and the ozone adsorbing capabilities were compared. Herein,the adsorbing towers were filled with 5 kg each of the high silicapentasyl zeolite with the SiO₂/Al₂O₃ ratio of 100, dealuminizedfogersite with the SiO₂/Al₂O₃ ratio of 70, mesoporous silicate with theSiO₂/Al₂O₃ ratio of 1000, and commercial silica gel.

[0098] In the water electrolytic ozone generating apparatus, gascontaining 10 vol. % of O₃, 87 vol. % of O₂, and 3 vol. % of H₂O (ozoneconcentration 10%) was generated, and precooled by heat exchange withthe oxygen concentrated gas at a relatively low temperature flowing outfrom the adsorbing tower in the adsorbing process, and then cooled to anadsorbing temperature by a cooler, and supplied into the adsorbing towerin the adsorbing process at a gas flow rate of 15 m³ N/h, and ozone wasadsorbed. On the other hand, in the adsorbing tower in the desorbingprocess, part of oxygen concentrated gas flowing out from the adsorbingtower in the adsorbing process was heated to a desorbing temperature of25° C., purge gas was passed in opposite direction of the gas flow inthe adsorbing process, and the ozone was heated, purged, desorbed, andrecovered. The adsorbing temperature was set at −30° C., −50° C. and−100° C., and the ozone concentration was experimented. The changeovertime of the adsorbing process and desorbing process, that is, the cycletime was set at 30 minutes, and the purge rate was set at about 1.5 byusing a regulating valve. The adsorbing pressure and desorbing pressurewere not particularly adjusted, and were about 1.05 atm.

[0099] The ozone concentration of the obtained ozone concentrated gaswas measured, and compared with the ozone concentration of the gasproduced in the water electrolytic ozone generating apparatus, and theozone concentration rate was determined, and the adsorbing temperatureand the ozone concentration rate are comparatively shown in FIG. 12. Asclear from this diagram, as compared with the silica gel, it is knownthat the dealuminized fogersite and mesoporous silicate show a verylarge ozone adsorbing capability. Incidentally, the small ozoneadsorbing capability of silica gel seems to be due to the effect ofmoisture in the gas containing ozone.

[0100] The adsorbing temperature may be selected in a range of −100 to−30° C., but considering the capacity of cooler for general use, theadsorbing temperature is preferred to be set at −60° C. or highertemperature.

Example 7

[0101] Using the mesoporous silicate having the largest ozone adsorbingcapability, and changing the cycle time from 10 min to 60 min, thetreating amount of gas containing ozone was investigated (m³ N/h/l tonof adsorbent). In this experiment, using the same apparatus in FIG. 8 asin Example 6, the ozone concentration was experimented same as inExample 6 except that the adsorbing temperature was set at −60° C. and−30° C. Results are shown in FIG. 13.

[0102] The ozone concentration of the gas containing ozone from thewater electrolytic ozone generating apparatus was 10 vol. %, but theozone concentration of the gas recovered in the desorbing process was 50vol. % (ozone concentration rate 5), and the ozone recovery rate was95%. As clear from the diagram, the treating amount is larger as theadsorbing temperature is lower and the cycle time is shorter, and aspecified treating amount is obtained by a relatively small amount ofadsorbent, and hence it is easy to reduce the size of the adsorbingtower, but a larger cooling energy is required.

Example 8

[0103] Using the mesoporous silicate same as in Example 7, and changingthe desorbing temperature from 0° C. to 75° C., the ozone concentrationrate was investigated, and the dependence of desorbing temperature wasstudied. In this experiment, too, using the same apparatus in FIG. 8 asin Example 6, the ozone concentration was experimented same as inExample 6, except that the adsorbing temperature was set at −60° C. and−30° C. Results are shown in FIG. 14.

[0104] As clear from FIG. 14, at the desorbing temperature of 75° C.,there was almost no difference in the ozone concentration rate betweenthe adsorbing temperature of −60° C. and −30° C., and the ozoneconcentration reaches its peak at the desorbing temperature of around20° C., and at the desorbing temperature of 0° C., the ozoneconcentration rate was 3 and 2 at the adsorbing temperature of −60° C.and −30° C., respectively. As the temperature became lower, thedifference in the ozone concentration rate began to increase, and at thedesorbing temperature of 0° C., the ozone concentration rate was 3 and 2due to difference in the adsorbing temperature.

What is claimed is:
 1. A manufacturing method of high concentrationozone gas, characterized by employing a pressure swing adsorbingapparatus having a plurality of adsorbing layers filled with ozoneadsorbent, adsorbing ozone by feeding gas containing ozone at arelatively high pressure into the adsorbing layers in the adsorbingprocess, and recovering concentrated ozone gas by setting the adsorbinglayers of the desorbing process to a relatively low pressure, whereinthe ozone adsorbent is one or two or more kinds of adsorbent selectedfrom the group consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate.
 2. A manufacturing method of highconcentration ozone gas according to claim 1 , wherein the adsorbinglayers in the adsorbing process are held at temperature of −60° C. to25° C.
 3. A manufacturing method of high concentration ozone gasaccording to claim 1 or 2 , wherein the adsorbing pressure in theadsorbing process is selected in a range of 1.05 to 5 atm, and thedesorbing pressure of the desorbing process is selected in a range of0.04 to 0.3 atm.
 4. A manufacturing method of high concentration ozonegas according to any one of claims 1 or 2, wherein the changeover timeof the pressure swing adsorbing apparatus is selected in a range of 1 to10 minutes.
 5. A manufacturing method of high concentration ozone gasaccording to any one of claims 1 or 2, wherein part of the high pressureoxygen concentrated gas flowing out from the adsorbing layers in theadsorbing process is decompressed by a reducing valve, and is fed intothe adsorbing layers in the desorbing process to be purged.
 6. Amanufacturing method of high concentration ozone gas according to claim5 , wherein the purge rate in the purge operation is selected in a rangeof 1 to
 2. 7. A manufacturing method of high concentration ozone gasaccording to any one of claims 1 or 2, wherein ozone is generated byusing a water electrolytic ozone generating apparatus of high pressure,the gas containing ozone is fed into the adsorbing layers in theadsorbing process of the pressure swing adsorbing apparatus, and part ofthe oxygen concentrated gas flowing out from the adsorbing layers in theadsorbing process is returned to the hydrogen electrode chamber of thewater electrolytic ozone generating apparatus to depolarize the oxygen.8. A manufacturing method of high concentration ozone gas according toany one of claims 1 or 2, wherein ozone is generated by using a silentdischarge ozone generating apparatus of high pressure, the gascontaining ozone is fed into the adsorbing layers in the adsorbingprocess of the pressure swing adsorbing apparatus, and part of the highpressure oxygen concentrated gas flowing out from the adsorbing layersin the adsorbing process is returned to the material side of the silentdischarge ozone generating apparatus.
 9. A manufacturing apparatus ofhigh concentration ozone gas, comprising an ozone generating apparatus,and a pressure swing adsorbing apparatus having plural adsorbing layersfilled with ozone adsorbent, wherein the ozone generating apparatus is awater electrolytic ozone generating apparatus of high pressure, theozone adsorbent is one or two or more kinds of adsorbent selected fromthe group consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate, a compressor and a changeover valveare attached to a lead pipe for feeding gas containing oxygen forconnecting the ozone generating apparatus to the adsorbing layers in anadsorbing process, a lead pipe for circulating oxygen concentrated gasflowing out from the adsorbing layers is connected to a hydrogenelectrode chamber of the water electrolytic ozone generating apparatusthrough the changeover valve so as to depolarize the oxygen, a lead pipefor feeding purge gas branched off the lead pipe for circulating oxygenconcentrated gas is connected to the adsorbing layers in a desorbingprocess through a reducing valve and changeover valve, and a controldevice is provided for changing over all the changeover valves to setthe adsorbing layers alternately in the adsorbing process and desorbingprocess by connecting a lead pipe for recovering ozone to the adsorbinglayers in the desorbing process through a changeover valve to recoverhigh concentration ozone gas.
 10. A manufacturing apparatus of highconcentration ozone gas, comprising an ozone generating apparatus, and apressure swing adsorbing apparatus having plural adsorbing layers filledwith ozone adsorbent, wherein the ozone generating apparatus is a silentdischarge ozone generating apparatus of high pressure, the ozoneadsorbent is one or two or more kinds of adsorbent selected from thegroup consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate, a compressor and a changeover valveare attached to a lead pipe for feeding gas containing ozone forconnecting the ozone generating apparatus to the adsorbing layers in anadsorbing process, a lead pipe for circulating oxygen concentrated gasat a relatively high pressure flowing out from the adsorbing layers isconnected to a lead pipe for feeding oxygen material of the silentdischarge ozone generating apparatus through the changeover valve, alead pipe for feeding purge gas branched off the lead pipe forcirculating oxygen concentrated gas is connected to the adsorbing layersin a desorbing process through a reducing valve and changeover valve,and a control device is provided for changing over all the changeovervalves to set the adsorbing layers alternately in the adsorbing processand desorbing process by connecting a lead pipe for recovering ozone tothe adsorbing layers in the desorbing process through a changeover valveto recover high concentration ozone gas.
 11. A manufacturing method ofhigh concentration ozone gas, using two or more adsorbing layers filledwith ozone adsorbent, employing a temperature swing adsorbing system fortransferring the adsorbing layers from an adsorbing process at arelatively low temperature to a desorbing process at a relatively hightemperature, and further returning to the adsorbing process, precoolingthe gas containing ozone from an ozone generating apparatus and feedinginto the adsorbing layers in the adsorbing process, discharging oxygenconcentrated gas at a relatively low temperature from the adsorbinglayers, passing purge gas at a relatively high temperature into theadsorbing layers in the desorbing process in an opposite direction ofthe gas flow in the adsorbing process, and recovering the concentratedozone gas continuously, wherein the ozone adsorbent is one or two ormore kinds of adsorbent selected from the group consisting of highsilica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, and the gas containing ozone from the ozone generatingapparatus is cooled by the oxygen concentrated gas at a relatively lowtemperature flowing out from the adsorbing layers in the adsorbingprocess.
 12. A manufacturing method of high concentration ozone gasaccording to claim 11 , using three or more adsorbing layers andemploying a temperature swing adsorbing system for transferring theadsorbing layers from an adsorbing process at a relatively lowtemperature to a desorbing process at a relatively high temperature, andfurther returning to the adsorbing process through a cooling process,wherein part of oxygen concentrated gas at a relatively low temperatureflowing out from the adsorbing process is fed into the adsorbing layersin the cooling process and is cooled.
 13. A manufacturing method of highconcentration ozone gas according to claim 11 or 12 , wherein part ofoxygen concentrated gas at a relatively low temperature flowing out fromthe adsorbing layers in the adsorbing process is heated to purgetemperature, and is passed into the adsorbing layers in the desorbingprocess in an opposite direction of the gas flow in the adsorbingprocess, and the ozone is heated, purged and desorbed.
 14. Amanufacturing method of high concentration ozone gas according to claim11 or 12 , wherein purge gas suited to the purpose of use of the highconcentration ozone gas is heated to purge temperature, and is passedinto the adsorbing layers in the desorbing process in an oppositedirection of the gas flow in the adsorbing process, and the ozone isheated, purged and desorbed.
 15. A manufacturing method of highconcentration ozone gas according to any one of claims 11 or 12, whereinthe purge rate in the purge operation is selected in a range of 1 to 2.16. A manufacturing method of high concentration ozone gas according toany one of claims 11 or 12, wherein the adsorbing temperature of theadsorbing process is selected in a range of −100° C. to −30° C., and thedesorbing temperature of the desorbing process is selected in a range of0° C. to 50° C.
 17. A manufacturing method of high concentration ozonegas according to any one of claims 11 or 12, wherein the adsorbingpressure of the adsorbing process is selected in a range of 1 to 4 atm.18. A manufacturing method of high concentration ozone gas according toany one of claims 11 or 12, wherein the changeover time of thetemperature swing adsorbing system is selected in a range of 10 to 60minutes.
 19. A manufacturing method of high concentration ozone gasaccording to any one of claims 11 or 12, using a water electrolyticozone generating apparatus as the ozone generating apparatus, whereinpart of the oxygen concentrated gas flowing out from the adsorbinglayers in the adsorbing process is returned to the hydrogen electrodechamber of the water electrolytic ozone generating apparatus todepolarize the oxygen.
 20. A manufacturing method of high concentrationozone gas according to any one of claims 11 or 12, using a silentdischarge ozone generating apparatus as the ozone generating apparatus,wherein part of the oxygen concentrated gas flowing out from theadsorbing layers in the adsorbing process is returned to the oxygenmaterial side of the silent discharge ozone generating apparatus.
 21. Amanufacturing apparatus of high concentration ozone gas, comprising anozone generating apparatus, and a temperature swing adsorbing apparatushaving plural adsorbing layers filled with ozone adsorbent, wherein theozone generating apparatus is a water electrolytic ozone generatingapparatus, the ozone adsorbent is one or two or more kinds of adsorbentselected from the group consisting of high silica pentasyl zeolite,dealuminized fogersite, and mesoporous silicate, a heat exchanger, acooler and a changeover valve are attached to a lead pipe for feedinggas containing ozone for connecting the ozone generating apparatus tothe adsorbing layers in an adsorbing process, a lead pipe forcirculating oxygen concentrated gas at a relatively low temperatureflowing out from the adsorbing layers is connected to the heat exchangerthrough the changeover valve, the gas containing ozone is precooled bythe oxygen concentrated gas at relatively low temperature in the heatexchanger, the outlet side of the oxygen concentrated gas at arelatively low temperature of the heat exchanger is connected to ahydrogen electrode chamber of the water electrolytic ozone generatingapparatus through a lead pipe, the oxygen concentrated gas at arelatively low temperature is supplied into the hydrogen electrodechamber to encourage the oxygen depolarization action, a lead pipe forfeeding purge gas is branched off from the lead pipe for circulating theoxygen concentrated gas at a relatively low temperature, and isconnected to the adsorbing layers in a desorbing process, a heater and achangeover valve are attached to the lead pipe for feeding purge gas tosupply the oxygen concentrated gas at relatively low temperature to theadsorbing layers as heating purge gas, the other end of the adsorbinglayers in the desorbing process is connected to a lead pipe forrecovering high concentration ozone gas through the changeover valve,and all the changeover vales are changed over simultaneously to use theadsorbing layers alternately in the adsorbing process and desorbingprocess.
 22. A manufacturing apparatus of high concentration ozone gas,comprising an ozone generating apparatus, and a merry-go-round typetemperature swing adsorbing apparatus having three or more adsorbinglayers filled with ozone adsorbent, wherein the ozone generatingapparatus is a water electrolytic ozone generating apparatus, the ozoneadsorbent is one or two or more kinds of adsorbent selected from thegroup consisting of high silica pentasyl zeolite, dealuminizedfogersite, and mesoporous silicate, a lead pipe for feeding gascontaining ozone from the ozone generating apparatus and a lead pipe forcirculating oxygen concentrated gas can be connected before and afterthe adsorbing layers in an adsorbing process, a lead pipe for feedingheating purge gas and a lead pipe for recovering high concentrationozone gas can be connected before and after the adsorbing layers in adesorbing process, a lead pipe for feeding cooling gas branched off fromthe lead pipe for circulating the oxygen concentrated gas and a leadpipe for recovery of the cooling gas can be connected before and afterthe adsorbing layers in a cooling process, the adsorbing process,desorbing process and cooling process are transferred sequentially byrotating the merry-go-round composed of the adsorbing layers, a heatexchanger and a cooler are attached to the lead pipe for feeding gascontaining ozone, the lead pipe for circulating oxygen concentrated gasis connected to the heat exchanger, the gas containing ozone isprecooled by the oxygen concentrated gas at relatively low temperatureflowing out from the adsorbing layers in the adsorbing process, and isfurther cooled to the adsorbing temperature by the cooler, the outletside of the oxygen concentrated gas at a relatively low temperature ofthe heat exchanger is connected to a hydrogen electrode chamber of thewater electrolytic ozone generating apparatus through a lead pipe, andthe oxygen concentrated gas at a relatively low temperature is suppliedinto the hydrogen electrode chamber to encourage the oxygendepolarization action.
 23. A manufacturing apparatus of highconcentration ozone gas, comprising an ozone generating apparatus, and atemperature swing adsorbing apparatus having plural adsorbing layersfilled with ozone adsorbent, wherein the ozone generating apparatus is asilent discharge ozone generating apparatus, the ozone adsorbent is oneor two or more kinds of adsorbent selected from the group consisting ofhigh silica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, a heat exchanger, a cooler and a changeover valve are attachedto a lead pipe for feeding gas containing ozone for connecting the ozonegenerating apparatus to the adsorbing layers in an adsorbing process, alead pipe for circulating oxygen concentrated gas at a relatively lowtemperature flowing out from the adsorbing layers is connected to theheat exchanger through a changeover valve, the gas containing ozone isprecooled by the oxygen concentrated gas at a relatively low temperaturein the heat exchanger, the outlet side of the oxygen concentrated gas ata relatively low temperature of the heat exchanger is connected to theoxygen material supply side of the silent discharge ozone generatingapparatus through a lead pipe so as to recycle the oxygen concentratedgas, a lead pipe for feeding purge gas is branched off from the leadpipe for circulating oxygen concentrated gas at a relatively lowtemperature and is connected to the adsorbing layers in a desorbingprocess, a heater and a changeover valve are attached to the lead pipefor feeding purge gas so that the oxygen concentrated gas at arelatively low temperature may be supplied to the adsorbing layers asheating purge gas, other end of the adsorbing layers in the desorbingprocess is connected to a lead pipe for recovering high concentrationozone gas through the changeover valve, and all the changeover valvesare changed over simultaneously to use the adsorbing layers alternatelyin the adsorbing process and desorbing process.
 24. A manufacturingapparatus of high concentration ozone gas, comprising an ozonegenerating apparatus, and a merry-go-round type temperature swingadsorbing apparatus having three or more adsorbing layers filled withozone adsorbent, wherein the ozone generating apparatus is a silentdischarge ozone generating apparatus, the ozone adsorbent is one or twoor more kinds of adsorbent selected from the group consisting of highsilica pentasyl zeolite, dealuminized fogersite, and mesoporoussilicate, a lead pipe for feeding gas containing ozone from the ozonegenerating apparatus and a lead pipe for circulating oxygen concentratedgas can be connected before and after the adsorbing layers in anadsorbing process, a lead pipe for feeding heating purge gas and a leadpipe for recovering high concentration ozone gas can be connected beforeand after the adsorbing layers in a desorbing process, a lead pipe forfeeding cooling gas branched off from the lead pipe for circulating theoxygen concentrated gas and a lead pipe for recovery of the cooling gascan be connected before and after the adsorbing layers in a coolingprocess, the adsorbing process, desorbing process and cooling processare transferred sequentially by rotating the merry-go-round composed ofthe adsorbing layers, a heat exchanger and a cooler are attached to thelead pipe for feeding gas containing ozone, the lead pipe forcirculating oxygen concentrated gas is connected to the heat exchanger,the gas containing ozone is precooled by the oxygen concentrated gas atrelatively low temperature flowing out from the adsorbing layers in theadsorbing process, and is further cooled to the adsorbing temperature bythe cooler, and the outlet side of the oxygen concentrated gas at arelatively low temperature of the heat exchanger is connected to oxygenmaterial supply side of the silent discharge ozone generating apparatusthrough a lead pipe so that the oxygen concentrated has can be recycled.